And it came to pass when Samuel was old, that he appointed his sons to be judges over Israel.

And it cometh to pass, when Samuel is aged, that he maketh his sons judges over Israel.

And it happened that, when Samuel had become old, he appointed his sons as judges over Israel.

This verse implies a long period, probably not less than 20 years, of which we have no account except what is contained in the brief notice in 1-Samuel 7:13-17. The general idea conveyed is of a time of peace and prosperity, analogous to that under other Judges.

When Samuel was old - Supposed to be about sixty.
He made his sons judges - He appointed them as his lieutenants to superintend certain affairs in Beer-sheba, which he could not conveniently attend to himself. But they were never judges in the proper sense of the word; Samuel was the last judge in Israel, and he judged it to the day of his death. See 1-Samuel 7:16.

And it came to pass, when Samuel was old, that he (a) made his sons judges over Israel.
(a) Because he was not able to bear the charge.

And it came to pass, when Samuel was old,.... The common notion of the Jews is, that he lived but fifty two years (t); when a man is not usually called an old man, unless the infirmities of old age came upon him sooner than they commonly do, through his indefatigable labours from his childhood, and the cares and burdens of government he had long bore; though some think he was about sixty years of age; and Abarbinel is of opinion that he was more than seventy. It is a rule with the Jews (u), that a man is called an old man at sixty, and a grey headed man at seventy:
that he made his sons judges over Israel; under himself, not being able through old age to go the circuits he used; he sent them, and appointed them to hear and try causes in his stead, or settled them in some particular places in the land, and, as it seems by what follows, at Beersheba; though whether that was under his direction, or was their own choice, is not certain.
(t) Seder Olam Rabba, ut supra. (c. 13. p. 35.) (u) Pirke Abot, c. 5. sect. 21.

It does not appear that Samuel's sons were so profane and vicious as Eli's sons; but they were corrupt judges, they turned aside after lucre. Samuel took no bribes, but his sons did, and then they perverted judgment. What added to the grievance of the people was, that they were threatened by an invasion from Nahash, king of the Ammonites.

OCCASIONED BY THE ILL-GOVERNMENT OF SAMUEL'S SONS, THE ISRAELITES ASK A KING. (1Sa. 8:1-18)
when Samuel was old--He was now about fifty-four years of age, having discharged the office of sole judge for twelve years. Unable, from growing infirmities, to prosecute his circuit journeys through the country, he at length confined his magisterial duties to Ramah and its neighborhood (1-Samuel 7:15), delegating to his sons as his deputies the administration of justice in the southern districts of Palestine, their provincial court being held at Beer-sheba. The young men, however, did not inherit the high qualities of their father. Having corrupted the fountains of justice for their own private aggrandizement, a deputation of the leading men in the country lodged a complaint against them in headquarters, accompanied with a formal demand for a change in the government. The limited and occasional authority of the judges, the disunion and jealousy of the tribes under the administration of those rulers, had been creating a desire for a united and permanent form of government; while the advanced age of Samuel, together with the risk of his death happening in the then unsettled state of the people, was the occasion of calling forth an expression of this desire now.

Old - And so unfit for his former travels and labours. He is not supposed to have been now above sixty years of age. But he had spent his strength and spirits in the fatigue of public business: and now if he thinks to shake himself as at other times, he finds he is mistaken: age has cut his hair. They that are in the prime of their years, ought to be busy in doing the work of life: for as they go into years, they will find themselves less disposed to it, and less capable of it. Judges - Not supreme judges, for such there was to be but one, and that of God's chusing; and Samuel still kept that office in his own hands, 1-Samuel 7:15, but his deputies, to go about and determine matters, but with reservation of a right of appeals to himself. He had doubtless instructed them in a singular manner, and fitted them for the highest employments; and he hoped that the example he had sent them, and the authority he still had over them, would oblige them to diligence and faithfulness in their trust.