Technical note / Defect ('illah): (1) In the manuscripts this name has been corrupted into "al-Dab'i", whereas the correct form is "al-Ghayfi" (with a fathah on the ghayn, a quiescent ya' and a fa' after it). It is an ascription to "Ghayfah". [See: al-Sam'ani's "al-Ansab".]

Grading: (2) "Abu Yahya al-Waqqar" (whose name is Zakariyya bin Yahya al-Misri) is "matruk" (abandoned) and "muttaham" (accused). About the engraving of the ring of Abu 'Ubaydah bin al-Jarrah, reports more authentic than this have been narrated through "mursal" routes.

Reference / Source: Among them is what 'Abd al-Razzaq (1361), Ibn Sa'd (3/381), al-Baladhuri in "Ansab al-Ashraf" (11/71-72) and Abu Nu'aym in "Ma'rifat al-Sahabah" (589) narrated through the route of Qatadah bin Di'amah as "mursal": that the engraving on the ring of Abu 'Ubaydah bin al-Jarrah was: "al-khumus lillah" (the one-fifth belongs to Allah). Its narrators are trustworthy.

Reference / Source: It was narrated by Ibn Abi Shaybah in "al-Musannaf" (8/269) from Mu'tamir bin Sulayman bin Tarkhan al-Taymi, from his father, as "mursal", like the narration of Qatadah: "al-khumus lillah". Its narrators are also trustworthy.

Reference / Source: It was narrated by Ibn Abi Shaybah (8/270) through the route of Mujahid bin Jabr, and (8/270) through the route of Ibrahim al-Nakha'i. Both of them narrated it as "mursal": that the engraving on the ring of Abu 'Ubaydah was: "al-hamdu lillah" (praise be to Allah). Its narrators are trustworthy.
Important point: This ("al-hamdu lillah") is more authentic, because the word "al-khumus" gives no meaning (here), and Allah knows best.