Mahabharata 3.82.124

तत्र मासं वसेद्वीर कौशिक्यां भरतर्षभअश्वमेधस्य यत्पुण्यं तन्मासेनाधिगच्छति

tatra māsaṃ vasedvīra kauśikyāṃ bharatarṣabhaaśvamedhasya yatpuṇyaṃ tanmāsenādhigacchati

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