Sahih Muslim Book 4, Hadith Number 1137.

Chapter : It is not advisable to pray wearing a cloth which has designs or markings over it.

Ibn ‘Umar reported: The Messenger of Allah (may peace be upon him) said: When the supper is served to any one of you and the prayer also begins. (in such a case) first take supper, and do not make haste (for prayer) till you have (taken the food).