“In that the leaders took the lead in Israel,
In that the people offered themselves willingly.
Bless you Yahweh.”
That leaders and people had responded to Yahweh's command through Deborah was an occasion for ‘blessing', that is giving praise and worship to, Yahweh. Without their willing response the victory would not have been achieved. We will learn later about those who did not respond.
The first phrase is difficult. It could be translated more literally ‘in that the loose (hair) hung loose in Israel'. This refers to the making of vows and the growing of the hair long, compare Samson (Judges 13:5), Samuel (1 Samuel 1:11) and the Nazirites (Numbers 6:5). Thus we could translate ‘in that those who made vows (to Yahweh) avowed themselves in Israel'. Compare the use of para‘ (loose) in Leviticus 10:6; Numbers 5:18.