Valmiki Ramayana Yuddha Kanda Sarga 24 Shloka 13

दाशरथिः Dasaratha's, रामः Rama, इतिलक्ष्मणम् thus to Lakshmana, समभाषत talked, तद्वै in that manner, शास्त्रदृष्टेन in accordance with what is said in sastras, कर्मणा the task, बलं army, विभजच्छ and divide.

Dasaratha's son Rama thus talked to Lakshmana in that manner and asked to divide the task of the army in accordance with what is said in sastras.