What is the explanation for combining the permissibility of interlacing fingers after prayer with the prohibition by the Messenger of Allah (peace and blessings be upon him) of interlacing fingers for one who has left intending to pray?

Interlacing fingers is prohibited for someone who is praying or is in the state of prayer, such as someone walking to the mosque or waiting for prayer within it. However, after finishing the prayer, there is no harm in it. The Prophet, peace and blessings be upon him, did it after the salutation of two rak'ahs in the story of Dhu al-Yadain, and he interlaced his fingers to illustrate the interconnectedness of believers, like a building.

The prohibition of interlacing fingers during prayer and before it is for the benefit of the prayer, as it may lead to fidgeting, drowsiness, or laziness, which is not suitable for the state of a worshiper.