Not when food is served or nature calls

Do not pray while food is ready or while holding back the toilet.

Narrated by Aishah

There is no prayer when food is served, nor when one is resisting the call of nature.

Sahih Muslim 560

What this hadith teaches

Islam wants the heart free in prayer, so it is better to eat or relieve oneself first, as long as the time of prayer does not run out.

Reference and grade

Grade
Sahih (in Sahih Muslim)
Narrator
Aishah

The hadith in Arabic نص الحديث

لاَ صَلاَةَ بِحَضْرَةِ الطَّعَامِ وَلاَ وَهُوَ يُدَافِعُهُ الأَخْبَثَانِ

Arabic text of Sahih Muslim 560, as given on sunnah.com.