tn The form is the Piel perfect with a vav (ו) consecutive (וּבֵרַכְתֶּם, uverakhtem); coming in the sequence of imperatives this perfect tense would be volitional—probably a request rather than a command.

sn Pharaoh probably meant that they should bless him also when they were sacrificing to Yahweh in their religious festival—after all, he might reason, he did let them go (after divine judgment). To bless him would mean to invoke good gifts from God for him.