Musannaf Ibn Abi Shaybah

Ibrahim says that whoever performs prayer while sitting should make his standing position cross-legged.

Sulaiman bin Bazee’ says that I went to Hazrat Salim; he was performing prayer while sitting. When he had to sit, he would place his knees on the ground, and when he had to stand, he would sit cross-legged.

Hazrat Sufyan says that if a person wishes to perform prayer while sitting, he should sit cross-legged during standing (qiyam). When he wishes to bow (ruku), he should bow cross-legged, and when he wishes to prostrate (sajdah), he should bend his leg.