What does fighting in the cause of Allah mean?

Re: What does fighting in the cause of Allah mean?

Ibn Jarir al Tabari was not a Shia. He was a sunni, and wrote two great works. The first one was on History, called History of the Prophets and Kings, famously known as Tarikh al Tabari, and the second one was his commentary on Quran, which is one of the most famous Tafsirs around, and many scholars have used it as their reference including Ibn Kathir.

But its true Tarikh al Tabari and Bidayah wal Nihayah the two greatest works on History of Islam, have many shiite narrations...and that's something thats true for all works on history. The thing is they get these shiite narrations with the perfect isnad and according to the methodology used for narrating hadith everything seems so spotless hence they are forced to add these narrations to their work.

Ibn Kathir had stated that despite of being so cautios as to not include anything that was unverified and false, he still couldn't get rid of shiite narrations from his work.

and, Bidayah wal Nihayah's sanad is from ibn Kathir? Ibn Kathir was born in 1301, he was a later day scholar, and he himself used Tabari as his reference lol.