called for a famine - as if it were a servant, ready to come at God’s bidding. Compare the centurion’s words, as to disease being God’s servant (Mat 8:8, Mat 8:9).
upon the land - namely, Canaan (Gen 41:54).
staff of bread - what supports life (Lev 26:26; Psa 104:15; Isa 3:1).