The ‘Thabat’ of Shaykh Mufti Muhammad Taqi Usmani by Shaykh Yasin Al-Fadani:
A Thabat work is essentially a collection of a scholar’s sanads to all the major and minor Hadith works. Since they consists of many chains, often Thabats can run into two volumes. The later the scholar, the more chains he will have to the books of Hadith.
Courtesy of Shaykh Ehzaz Ajmeri.