(43) General Behavior (Kitab Al-Adab)
كتاب الأدب
(97) Chapter: Regarding yawning
(97) باب مَا جَاءَ فِي التَّثَاؤُبِ
Sunan Abi Dawud 5027 
The tradition mentioned above has also been transmitted in a similar way by Suhail through a different chain of narrators. This version has; “during prayer, so he should hold as far as possible”.
حَدَّثَنَا ابْنُ الْعَلاَءِ، عَنْ وَكِيعٍ، عَنْ سُفْيَانَ، عَنْ سُهَيْلٍ، نَحْوَهُ قَالَ ‏ "‏ فِي الصَّلاَةِ فَلْيَكْظِمْ مَا اسْتَطَاعَ ‏"‏ ‏.‏
Grade :  Sahih (Al-Albani) صحيح  (الألباني)حكم :
Reference : Sunan Abi Dawud 5027
In-book reference : Book 43, Hadith 255
English translation : Book 42, Hadith 5009