Should sleep and rise (kaqeudh kai egeirhtai). Present subjunctive for continued action. So also spring up and grow (blastai kai mhkunhtai) two late verbs. The process of growth goes on all night and all day (nukta kai hmeran, accusative of time). He knoweth not how (w ouk oiden auto). Note position of w (beginning) and auto (end) of clause: How knows not he. The mystery of growth still puzzles farmers and scientists of today with all our modern knowledge. But nature's secret processes do not fail to operate because we are ignorant. This secret and mysterious growth of the kingdom in the heart and life is the point of this beautiful parable given only by Mark. "When man has done his part, the actual process of growth is beyond his reach or comprehension" (Swete).