tn The Hebrew text simply has “I have received [to] bless.” The infinitive is the object of the verb, telling what he received. Balaam was not actually commanded to bless, but was given the word of blessing so that he was given a divine decree that would bless Israel.
sn The reference is probably to the first speech, where the Lord blessed Israel. Balaam knows that there is nothing he can do to reverse what God has said.
tn The verb is the Hiphil of שׁוּב (shuv), meaning “to cause to return.” He cannot return God’s word to him, for it has been given, and it will be fulfilled.