Poole on 1 Samuel 8:1: Samuel in Old Age
[circa 1112] Verse 1: And it came to pass, when Samuel was old, that he (Deut. 16:18; 2 Chron. 19:5) made his (see Judg. 10:4; 12:14, compared with Judg. 5:10) sons judges over Israel.
[When Samuel had grown old] And so, feeling himself to be incapable of bearing many labors, he set aside the burden with honor (Mendoza). When he was no longer vigorous enough to be able to make the circuit of the cities of Israel for the purpose of administering justice (Vatablus). At this time, Samuel was about sixty years of age, and after these things he made Saul king, and lived with him for sixteen years (Mendoza, Tostatus).
[He positioned his sons as judges] In his place (Grotius). Either, 1. as supreme judges, as Carthusianus and Augustine appear to think (Mendoza, similarly Martyr). Not inferior Judges, that they might settle minor cases (for that was allowed to all Levites): but he had appointed them in his place, and had put them in the same degree of honor. Otherwise, the people, afflicted with injuried, would have appealed from them to other judges: But no such appeal was allowed from the supreme power (Martyr). Or, 2. Inferior Judges, his deputies, as it were; in such a way that Samuel himself was the supreme Judge, was settling the most important cases himself, and was requiring the rest to be settled by his sons (Lapide out of Tostatus). He committed only a delegated power to his sons. It is proven, 1. Because Samuel judged all the days of his life. 2. Samuel is always reckoned as the greatest of the Judges. 3. When the people asked for a king, they are said to have despised God and Samuel, not Samuel’s sons. It did not belong to Samuel, but to God, to set up supreme Judges (Mendoza). Some think that Samuel slipped here (thus Martyr). Because he did not consult the Lord is so great a matter, as Moses did; neither did he, like Gideon, refuse rule. Perhaps, in his humanity, he was touched by some ambition, to retain the magistracy in his own family. Although it was possible, that he did that with a good intention: either because he saw them to be of good quality: or because by his domestic example he was hoping that they were going to be better: Or, he knew that he was going to have rule over them, if they should offend in anything (Martyr). He made them Judges, because he had given them the best education, and we judging them more worthy than the rest; and perhaps they were such at the beginning, but honors change manners, but rarely for the better (Lapide out of Dionysius).
When Samuel was old, and so unable for his former travels and labours, he made his sons judges; not supreme judges, for such there was to be but one, and that of God’s choosing, and Samuel still kept that office in his own hands, 1 Samuel 7:15; but his vicegerents or deputies, who might go about and determine matters, but with reservation of a right of appeals to himself. He advanceth his sons to this place, not so much out of paternal indulgence, the sad effects whereof he had seen in Eli; but because he had doubtless instructed them in a singular manner, and fitted them for the highest employments; and he hoped that the example he had set them, and the inspection and authority he still had over them, would have obliged them to diligence and faithfulness in the execution of their trust.
 Hebrew: וַיְהִ֕י כַּאֲשֶׁ֥ר זָקֵ֖ן שְׁמוּאֵ֑ל וַיָּ֧שֶׂם אֶת־בָּנָ֛יו שֹׁפְטִ֖ים לְיִשְׂרָאֵֽל׃  See 1 Samuel 8:7.  See Numbers 27:15-23.  See Judges 8:22, 23.