To fill the hand is an interesting Hebrew idiom. Overall, it occurs about twenty times in the Hebrew Bible. It is most often connected with the consecration of the Levitical priests. In Exod 28:41, God instructs Moses: “you shall anoint [Aaron and his sons], and fill their hand, and consecrate them, and they shall function as priests for me.” See also Exod 29:9, 33, 35; Lev 8:33; 16:32; 21:10; Num 3:3. The expression is also used of the illegal ordination of priests. Micah the Ephraimite filled the hand of one of his sons, and the hand of the infamous Levite, to be priests (Judg 17:5, 12). See also 1 Kgs 13:33; 2 Chr 13:9.
The expression typically has the Piel of מלא with יד as its object. It is usually understood as an idiom that means to consecrate or to ordain, but what is the connection between filling the hand and ordination? The root מלא in the Piel means to fill. The word יד, which means hand, can have the extended meaning of power. The idiom seemingly communicates, therefore, the idea of conferring power or authority. To fill the hand of a person is to complete the power of that person in the sense of authorizing that person for a particular task.
There is a concrete example of this expression in the Scriptures which seems to illuminate this idiom. In 2 Kgs 9:24, we are told that “Jehu filled his hand in the bow.” In other words, Jehu put his strength into the bow to draw it back strongly for a powerful shot aimed at King Joram. Here to fill the hand means to transfer power. This seems to confirm the idea that filling the hand of someone to be priest means to authorize, hence to ordain as priest.
However, the expression can also be used of ordinary people who consecrate themselves in the service of God. David is recorded as using the expression in 1 Chr 29:5 to encourage the people to give freewill offerings to the Lord to be used in the the building of the temple. Here the people are effectively called upon to fill their own hands in the service of God! A similar idea is found in 2 Chr 29:31 where the people fill their hands by joining with Hezekiah in renewing the covenant before God. And finally, the expression can also be used of objects dedicated for the worship of God. The priests in Ezekiel’s vision of the eschatological temple would offer sacrifices to purify and to fill the hand of the altar of the temple (Ezek 43:26).
There is one particular use of this expression that deserves to be mentioned. After the sin of the golden calf, Moses proclaimed: “Whoever is on the Lord’s side, come to me!” (Exod 32:26). When the sons of Levi gathered around him, Moses told them to take their swords and to execute judgment upon the people. He also encouraged them at this time: “Fill your hands today to Yahweh, yes, every man against his son and against his brother!” (Exod 32:29). Having understood the logic behind the idiom, Moses’ use of the expression at this juncture surely appears to be a case of deliberate double entendre. The Levites were to consecrate themselves to God by unleashing the power of their hands against their rebellious countrymen.