In his doctrine - In his "teaching," for so it should be rendered.
Beware of the scribes - Be on your guard. Be cautious about hearing them or following them.
Scribes - The learned men of the Jewish nation.
Which love to go in long clothing - In long, flowing robes, as significant of their consequence, leisure, and learning.
Salutations - See the notes at Matthew 23:6-7.

Beware of the scribes - See on Matthew 23:1 (note), etc.

(6) And he said unto them in (g) his doctrine, Beware of the scribes, which love to go in (h) long clothing, and [love] salutations in the marketplaces,
(6) The manners of ministers are not to be followed rashly as an example.
(g) While he taught them.
(h) The word is a "stole", which is a kind of woman's garment that goes down even to the heels, and is taken generally to refer to any pleasant looking garment, but in this place it seems to signify the fringed garment mentioned in (Deuteronomy 22:12).

And he said unto them in his doctrine,.... As he was preaching, not to the Scribes and Pharisees but to the multitude, and to his disciples particularly; and to them in the audience of the people, as appears from Matthew 23:1.
Beware of the Scribes; for though he had just spoken favourably of one of them, this was but a single man, and a singular instance; the body of that set of men, were very bad in their principles and practices, and therefore to be avoided, and that for the reasons following:
which love to go in long clothing; the Persic version renders it, "who affect to walk in coats and garments conspicuous, and in long robes"; such as were very particular, and different from others, and out of the common way of apparel; and so were observable and taken notice of by others: very likely it may have reference to the common length of their fringes on the borders of their outward garment, which they enlarged beyond others; See Gill on Matthew 23:5;
and love salutations the market places; or "streets", as the Syriac and Arabic versions render it, in any public places, where there was a resort of men, and they were taken notice with respect, in a public manner. The Syriac Persic supply the word "love", as we do from Matthew 23:6; see Gill on Matthew 23:6, Matthew 23:7.

And he said unto them in his doctrine--rather, "in His teaching"; implying that this was but a specimen of an extended discourse, which Matthew gives in full (Matthew. 23:1-39). Luke says (Luke 20:45) this was "in the audience of all the people said unto His disciples."
Beware of the scribes, which love--or like.
to go in long clothing--(see on Matthew 23:5).
and love salutations in the market-places,

Beware of the scribes. Mark gives in three verses his report of the wonderful discourse recorded in Matthew, chapter 23. These three verses are parallel to Matthew 23:5-6, Matthew 23:14. See notes there. Compare Luke 20:45-47.
Love to go in long clothing. Peculiar to Mark. Long, flowing robes, reaching to the feet, similar to those worn by Romish priests, and were worn by the scribes as a kind of professional attire, in order to attract attention. When Christ sent his apostles out to preach, he directed that they should be clothed as the common people (Mark 6:9; Matthew 10:10). The scribes, ancient and modern, love display, showing themselves off in the chief places of concourse. They love appellations of honor and respect, such as Rabbi, Father, Master, Teacher. Men often profess a desire to magnify their office, when in truth they want to magnify themselves. They love robes that advertise to every one that they are separate from the rest of the people.

Beware of the scribes - There was an absolute necessity for these repeated cautions. For, considering their inveterate prejudices against Christ, it could never be supposed the common people would receive the Gospel till these incorrigible blasphemers of it were brought to just disgrace. Yet he delayed speaking in this manner till a little before his passion, as knowing what effect it would quickly produce. Nor is this any precedent for us: we are not invested with the same authority. Matthew 23:5; Luke 20:46.