And layeth aside his garments. The meaning is, that he laid aside his upper garment, not his coat; for we know that the inhabitants of Eastern countries wore long garments

He riseth from supper - Evidently while they were eating. See John 13:2.
Laid aside his garments - His outer garment. See the notes at Matthew 5:40. This was his mantle or robe, which is said to have been without seam. It was customary to lay this aside when they worked or ran, or in the heat of summer.
Took a towel and girded himself - This was the manner of a servant or slave. See the notes at Luke 17:8.

He riseth from supper - Not from eating, as Bishop Pearce has well observed, but from his place at table; probably the dishes were not as yet laid down, though the guests were seated. According to the custom of the Jews and other Asiatics, this washing must have taken place before the supper. See on John 13:2 (note).
Laid aside his garments - That is, his gown or upper coat, with the girdle wherewith it was girded close to his tunic or under coat; and, instead of this girdle, he tied a towel about him:
1. that he might appear in the character of a servant; and
2. that he might have it in readiness to dry their feet after he had washed them.

He (c) riseth from supper, and laid aside his garments; and took a towel, and girded himself.
(c) In that he is said to rise, it argues that there was a space of time between the ceremony of the passover and this washing of feet, at which time it seems that the Lord's supper was instituted.

He riseth from supper,.... In the midst of the entertainment, and which no doubt was considerable, his mind being intent on something else; and it being his meat and drink to do his Father's will, he rises and leaves his disciples sitting to finish their meal; and whilst they were murmuring at the waste of the ointment poured on his head, and were filled with indignation at it, as they all of them were, see Matthew 26:8; he rises up to wash their feet; amazing patience and humility!
And laid aside his garments; not all his garments, only his upper ones, that he might better dispatch the business he was going about; and which was an emblem of his laying aside, as it were for a while, his glory and dignity as the Son of God, and of his appearing in the form of a servant.
And took a towel; or "linen cloth", the same with in the Jerusalem Talmud (r):
and girded himself; with the towel, or linen cloth, which served both for a girdle, and after he had washed his disciples' feet, to wipe them with. This was a servile habit; so servants used to stand at the feet of their masters, girt about with a linen cloth (s); and shows, that the son of man came not to be ministered unto, but to minister.
(r) Sabbat, fol. 3. 1. & 12. 1. (s) Suetonius in Caligula, c. 26.

He riseth from supper, and laid aside his garments--outer garments which would have impeded the operation of washing.
and took a towel and girded himself--assuming a servant's dress.

He riseth from supper, and laid aside his garments. Shortly after they had sat down to the table, he arose, laid aside his outer robe, girded a towel upon him, and began the lowly office of washing the feet of twelve men, without a word of explanation. Something more than ordinary must have caused so remarkable an act. The fact that the cause has been lost sight of, has caused many to misunderstand the significance, and to think the Savior was instituting a church ceremonial, rather than giving a deep, practical, spiritual lesson for all ages. I will endeavor to explain the circumstances: (1) The disciples still expected the immediate manifestation of the kingdom. When they sat down to this Supper they felt it was a kind of state occasion, and a strife arose among them for precedence. Each wanted the "chief seat at the feast." An account of this unseemly controversy over the old question, "Who should be greatest?" is found in Luke 22:24-30. (2) Their sandals had been laid off according to custom. They sat down to the table with dry and dusty feet, but no one brought water to wash their feet, an eastern duty of hospitality made necessary by their hot, dusty climate. No apostle volunteered to attend to the office, the duty of a servant. (3) Then, while they were filled with their ambitious, envious feelings, and had engaged in strife right at the Lord's table, after waiting long enough to have it shown that no one would condescend to the menial, but needful duty, the Lord, full of conscious divinity, arose, girded on the towel, and began the office. A rebuke to their ambitious strife, far more powerful than words could have spoken: such a rebuke that never again do we see a hint of the old question, "Who should be greatest?" It was Christ's answer to their unseemly conduct, and a lesson to those Christians "who love the pre-eminence" for all time. It said, "Let him that would be greatest become the servant of all."

Layeth aside his garments - That part of them which would have hindered him.