Deuteronomy 33:8
And of Levi he said, Let thy Thummim and thy Urim be with thy holy one, whom thou didst prove at Massah, and with whom thou didst strive at the waters of Meribah;
And of Levi he said,.... That is, Moses said of the tribe of Levi, as both the Targums of Jonathan and Jerusalem:
Let thy Thummim and thy Urim be with thy holy one; with Aaron, as the same Targums interpret it, who was of the tribe of Levi, and was a holy good man, a saint of the Lord, as he is called, Ps 106:16; of the Urim and Thummim, which were with him and with every high priest,
See Gill on "Exodus 28:30"; and though they were not in use under the second temple, yet had their fulfilment in Christ the antitype of Aaron, who may be chiefly here intended; who is after called the Lord's Holy One, as he is, both as God and man, holy in both his natures, divine and human, and in his life and actions; and with him are the true Urim and Thummim, lights and perfections, the light of nature, grace and glory, and all perfections, both divine and human;
See Gill on "Exodus 28:30" {i}:
whom thou didst prove at Massah, and with whom thou didst strive at the waters of Meribah; which, as it may respect Aaron, may be understood either of the Lord's proving him and contending with him, by suffering the children of Israel to murmur against him and Moses, at the said places; when, according to the three Targums, he stood in the temptation, and was perfect and found faithful; or of Levi, who, with the rest of the tribes, tried him, and strove with him at the same places; though Jarchi says they did not murmur with the rest that murmured: as it may refer to Christ the antitype of Levi, the sense is, that the Urim and Thummim should be with the Holy One, the Messiah, whom thou, O Levi, with the rest of the tribes, tempted and strove with at the places mentioned; for it is expressly said, they tempted the Lord, Exodus 17:7; and which is interpreted of Christ, 1 Corinthians 10:9.
{i} See a Sermon of mine on this text, called "Levi's Urim and Thummim Found with Christ".