Mahabharata 3.163.28

अणुर्बृहच्छिरा भूत्वा बृहच्चाणुशिराः पुनःएकीभूतस्तदा राजन्सोऽभ्यवर्तत मां युधि

aṇurbṛhacchirā bhūtvā bṛhaccāṇuśirāḥ punaḥekībhūtastadā rājanso'bhyavartata māṃ yudhi

Our plain-language meaning of this verse is waiting for scholar review.