As noted elsewhere, the expression have given the hand to
refers to the confirmation of an agreement or allegiance between persons or parties (see Ezekiel 17:18; 1 Chronicles 29:24; 2 Chronicles 30:8). In this context there are two suggestions of how it should be understood.
First, it could be seen as a reference to past foreign policy (see notes elsewhere). In this case it was Judah who reached out to Egypt and Assyria to form an alliance against the Babylonian threat. Although such alliances were formed, they did not deliver Judah, as these nations did not help Jerusalem.
Second, it could be understood as a reference to the people of Jerusalem who fled to other countries, desperately seeking food. It is suggested that they would even subject themselves to this foreign authority in the hope that they might survive (see also Jeremiah 40:11–16; Jeremiah 41:1; Jeremiah 42:14–18).1 As already mentioned (see notes elsewhere), the reference here is not concerning the past but the current need of famine relief: to get enough bread.
The better option would be to understand this verse in the latter context.
However, this raises the question of the reference to Assyria,
as it was not a military or political power anymore. The answer to this problem is found in the fact that although Assyria ceases to exist as a power, the term was still in use (see Ezra 6:22; Zechariah 10:10). Furthermore, it is also possible that these requests were not addressed to the literal authorities of those countries, but to the Jewish refugees who had settled in these areas.2 Therefore, the reference to Egypt and Assyria is a traditional way of describing foreign territory. It is also suggested that the combination of Egypt and Assyria is a conventional word pair used in that time, symbolically. This reference was used figuratively to denote false alliances and places of exile. Judah continued to suffer from past alliances and presently must go abroad for food, asking the same people who either defeated them or failed to help them in the past.3
6 We have given the hand to Egypt, and to Assyria, to get bread enough.