What is the meaning of the forbidden Al-Nasi' (the postponement) in verse 37 of Sūrat At-Tawbah, and what type of Nasīʾ was common in the Arabian Peninsula before its prohibition?

The noble verse states: (Indeed, postponement [of sacred months] is an increase in disbelief). There has been a difference of opinion regarding the meaning of "postponement" (an-Nasi'). The most well-known interpretations include the Arabs replacing some of the sacred months with others for the purpose of fighting, thus making the month of Muharram permissible (for fighting) and making Safar sacred in its place. The first to do this was "al-Qalammas," who was Hudhayfah ibn Abd Mudrikah, and his sons continued this practice until Junadah ibn Awf. Islam was established during his time. He would make Muharram permissible one year and sacred the next, to align with the number of months Allah had made sacred.