Did Imam “Sadiq” [AS] appoint “Ismail” as Imam?
Notice: [BADA’] means: god changes what he has distained because god would rather to distain something in one way and then it’s fulfilled in another way and it’s because of interests that we some of them and don’t know some of them.
The answer of this question is available in the oldest Shiite belief-resources .
قول الصادق عليه السلام : ما بدا لله بداء كما بدا له في إسماعيل ابني ،
يقول : ما ظهر لله أمر كما ظهر له في إسماعيل ابني إذ اخترمه قبلي ليعلم بذلك أنه ليس بإمام بعدي .
Imam “Sadiq’s [AS] talk: There wasn’t “Bada’” for god like what was made for my son “Ismail”
Imam says: no state was disclosed from god [in terms of being surprise for people], as it was done about my son “Ismail”, because god got his life before me [he died] till all know that he’s not Imam after me.
Al-Tuhid, Al-Sheikh Sadooq, p 336
“Ismail” was the eldest son of Imam “Sadiq” [AS] and naturally and according to what was common among people he should have become Imam, because Shiites have narrative which says:
الأمر في الكبير ما لم تكن فيه عاهة
Imamate is for the eldest son, unless he has disease [that makes people turn their back on him]
Al-Kafi, v 1, p 258
Of course this narrative hasn’t reached to us with valid document –in terms of “Rejal” science- and “Sahl ibn Ziyad Abu Yahya Al-Vaseti” -who is Shiite- is in the document of this narrative, but his reliability hasn’t been proved. And distorting the concept of this narrative caused the astray of some of Shiites after the martyrdom of Imam “Sadiq” [AS], because “Abdullah ibn Aftah” another son of Imam Sadiq [AS], was older than Imam “Kazim” [AS], so some distorted this narrative and removed the its last part which says Imam shouldn’t have physical problem to prove that “Abdullah” is the Imam After Imam “Sadiq” [AS]. His head didn’t have natural shape that’s why he was called “Aftah”.
But according to the narratives quoted by “Ahl Al Bayt”, the Imam after Imam Sadiq [AS] is his another son “muses ibn Ja’far” [Imam “Kazim”] and this issue had made doubt for people. That’s why god got the life “Ismail” when his father [Sadiq] was alive till everybody knows that next Imam is “Kazim” [AS].
This issue that “Ismail” is dead was strange for people; because they would think that he’ll be next Imam but god fulfilled his promise.