According to “Ordination In the Old Testament” by Afolarin Olutunde Ojewole, Ph.D.
"The phrase “fill the hand,” containing the word mālēᵓ is translated as “consecrate” or “ordain.” The phrase ultimately became the idiomatic expression for “installing a priest into office,” or “ordination” . See passages like: Exod 28:41; 29;9, 35; 32:29; Lev 8:33; 16:22; 21:10; Num 3:3; Judges 17:5, 12; 1 Kings 13:33; 1 Chron 29:5; 2 Chron 13:9; 29:31. This could have originated from the wages or support a priest received for his services as evidenced in Judges 17 where Micah made his son a priest by ‘filling his hand’ with silver (17:5) and later hiring a Levite and paying him for his priestly services (17:10-12). It could reflect the practice of filling the priest’s hands with the offerings of the sacrificial animals as the reason for the term. In Lev 8:25-29, Moses placed portions of the sacrificial ram and cake offerings in the hands of Aaron and his sons to offer them as a wave offering to God and later consumed them on the altar as “an ordination offering for a soothing aroma” to the Lord (Beck, 1962, p. 667). Numbers 3:3 reads: “These are the names of the sons of Aaron, the anointed priests, whom he consecrated to minister as priests.” The multiplication of verbs that refer to cultic actions in this short verse is interesting:lemallôt yādô , literally, “fill his hand” meaning “consecrate himself.” This has no cultic connotation but that they commit themselves and their services to God whole-heartedly and sacrificially. In Judges 17:5, a man named Micah made a shrine and installed one of his sons as the priest for it. He waymallēᵓ ᵓet-yad , literally “filled the hand of” meaning “he consecrated.” Later on in Judges 17:12, Micah had found a Levite to install as his personal priest instead; literally: “Micah filled the hand of the Levite” meaning “Micah consecrated the Levite.” Like Numbers 3:3, these two verses have strong cultic connotations pointing to some form of “ordination.” In Numbers 3:3, the phrase millē yādā, as a figure of speech, it literally means: “fill their hand,” thus describing the ceremonial rite of ordination (Kiel & Delitzsch, 1973). This signified two things for the ordination of priests. First, it represented the duty and privilege the priest had in making offerings to the Lord on behalf of others. Second, it represented that the Lord would indeed fill their hand in the sense of providing for the material needs of the priests, representing God’s sufficiency. “‘To fill one’s hand’ (with sacrifices) is ‘to consecrate’ one’s service (1 Chron 29:5; Exod 32:29) or a priest (Judges 17:5)” (Kaiser, p. 506). In Exodus 32:29, after the molten calf experience, Moses told all the children of Israel to milᵓû yedḵem , literally, “fill your hand” meaning “consecrate yourselves.” This has no cultic intention but just that they confess their sins, and re-dedicate themselves to serving God alone.
According to the writer the term מִלֵּא יָדָם could be used with non-priests ,to mean " confess ones sins, and re-dedicate himself to serving God alone" ...
in one Jewish apocalyptic text (testament of Moses):
"And then His kingdom shall appear throughout all His creation, And then Satan shall be no more, And sorrow shall depart with him. Then "the hands of the angel shall be filled." Who has been appointed chief, And he shall forthwith avenge them of their enemies. For the Heavenly One will arise from His royal throne, And He will go forth from His holy habitation With indignation and wrath on account of His sons."
Why did the writer use The phrase “fill the hand,” with an angel? what is his intention behind such strange usage? why do the hands of an angel shall be filled (as a priest ),for a mission of revenge?