What is the meaning of Abu Hatim's saying about a narrator: "Salih al-Hadith" (sound in hadith), and does it mean that his hadith is good (hasan) and can be used as evidence, or is it one of his terms of disparagement (jarh)?

The meaning of Abu Hatim al-Razi's statement about a narrator: "His hadith is Salih (acceptable)," is that his hadith is suitable for consideration in corroborating evidence (shawahid) and supporting narrations (mutaba'at), but it is not used as a primary proof (hujjah) when he narrates it alone. This is the original meaning of this term. However, the intended meaning may vary depending on the context. He might intend that it is suitable for use as a primary proof even when narrated alone if he states something to that effect. The lowest ranks of commendation (ta'deel) and the lightest ranks of disparagement (tajreeh) share the same ruling: their hadith is suitable for consideration and corroborating evidence, but it is not used as a primary proof when narrated alone.