شمر للأمر

شَمّرَ لِلأمْر، شَمّرَ عَنْ ساعِدِهِ أو عَنْ ساعِدِ الجِدّ

to get ready for, prepare oneself for, gird oneself for, gird (up) one's loins for; to buckle down to, knuckle down to, apply oneself to, get to work, embark upon, set out to