It is narrated from Hazrat Abu Laila (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) observed i'tikaf in a tent made of palm leaves.
Hadith Referenceمسند احمد / تتمہ مُسْنَدِ الْكُوفِيِّينَ / 19061
Hadith Gradingحکم دارالسلام:إسناده ضعيف لضعف على بن عابس