Natyashastra
कालप्रकर्षहेतोश्च पादानां प्रविभागतः । सूत्रधारप्रवेशाद्यो वन्दनाभिनयान्तकः ॥ ७४॥
Due to the progression of time and the division of the acts, the first act, which concludes with the gesture of salutation, begins with the entrance of the stage-manager.
english translation
kAlaprakarSahetozca pAdAnAM pravibhAgataH । sUtradhArapravezAdyo vandanAbhinayAntakaH ॥ 74॥
hk transliteration by Sanscript