Musannaf Ibn Abi Shayba 3:5559

Ibn Numayr narrated to us, from Zam'ah, from 'Uthman ibn al-Zubayr, from Yahya ibn Ja'dah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "The *rabbi* shall not approach the prayer." It was said: "O Messenger of Allah, and what is the *rabbi*?" He said: "The one who finds *rabw* (shortness of breath/asthma) in his stomach."