Researching the chain of a hadith that contains an explicit mention of hearing despite the presence of the term "an" (from).

The questioner : The hadith of al-Tirmidhi from Ibn Ghaylan: Abu Dawud narrated to us, from Shu'bah, from al-A'mash, from Zayd, from Ibn Abbas. And Ahmad narrated from al-Fadl ibn Iyad, from Shu'bah, from al-A'mash, from Mujahid, from Ibn Abbas... In Shu'bah's narrations from Mujahid, he never used the word "I heard"; meaning, he did not explicitly state that he heard it; so it is from Abu Yahya, and al-Fadl ibn Iyad explicitly stated in his narration from Shu'bah: "from Abu Yahya"; so does this explicit mention alongside the use of "an" (from) necessitate the continuity of the chain with... or not?

The Shaykh : What...?

The questioner : ... .

The Shaykh : ... .

The questioner : No, I mean, does the ruling on Shu'bah's narration from al-A'mash from Abu Yahya al-Qattat, where he used "an" (from) and he is naturally a tadlis narrator;... al-A'mash's narration from Mujahid that it is from Abu Yahya al-Qattat; is the chain ruled as continuous on this basis, even though he did not say "I heard from Abu Yahya," but said "from Abu Yahya"?

The Shaykh : Fine; before I answer this question; what is the benefit of researching the science of hadith?

The questioner : Knowing the authenticity of a hadith from its weakness.

The Shaykh : Fine; now... is this the benefit or what?

The questioner : I am currently studying in this field, yes.

The Shaykh : ... Fine; if we say: the hadith is connected, what did you benefit from?

The questioner : ... From other routes.

The Shaykh : No, what did you benefit from? Did its chain become authentic?
... ...

The questioner : It would be a corroborating narration to Shu'bah's narration.

The Shaykh : ... You are researching a voluntary aspect of knowledge, may Allah forgive you!