One of the users have posted about a story from shatapatha brAhmaNa about cutting head of the god.
From this answer of @KeshavSrinivasan,
The connection between Vishnu and the Sun is described in this chapter of the Shatapatha Brahmana of the Yajur Veda. The gods once accidentally cut off Vishnu's head with his own bow (this is all Vishnu's Lila, of course) and the head turns into the Sun:
They spake, 'Whoever of us, through austerity, fervour, faith, sacrifice, and oblations, shall first compass the end of the sacrifice, he shall be the most excellent of us, and shall then be in common to us all.' 'So be it,' they said. Vishnu first attained it and he became the most excellent of the gods; whence people say 'Vishnu is the most excellent of the gods.' Now he who is this Vishnu is the sacrifice; and he who is this sacrifice is yonder Âditya (the sun). ... Taking his bow, together with three arrows, he stepped forth. He stood, resting his head on the end of the bow. Not daring to attack him, the gods sat themselves down all around him. Then the ants said--these ants (vamrî), doubtless, were that (kind called) 'upadîkâ'--'What would ye give to him who should gnaw the bowstring?'--'We would give him the (constant) enjoyment of food, and he would find water even in the desert: so we would give him every enjoyment of food.'--'So be it,' they said. Having gone nigh unto him, they gnawed his bowstring. When it was cut, the ends of the bow, springing asunder, cut off Vishnu's head. It fell with (the sound) 'ghriṅ'; and on falling it became yonder sun. And the rest (of the body) lay stretched out (with the top part) towards the east. And inasmuch as it fell with (the sound) 'ghriṅ,' therefrom the Gharma (was called); and inasmuch as he was stretched out (pra-vrig,), therefrom the Pravargya (took its name).
Does the text itself mention explicitly that it was Lord's Leela or is it a speculation ?
Where does the shatapatha brAhmaNa say about leelas of the Lord explicitly ?