‘There is no God but Allah’ is the declaration of faith, the first step towards good deeds and acquiring the pleasure of the Most Merciful, and a means of repelling Satan
المصدر : غرر الحكم ودرر الكلم
التَّوْحِيدُ أَنْ لَا تَتَوَهَّمَ
Belief that Allah is one means that you should not [try to] imagine [Him]
Everyone who is called ‘one’ other than Allah, the Glorified, is little; and every honoured one other than Him is inferior; and every strong one other than Him is weak; and every master other than Him is a slave; and every knower other than Him is a learner; and every capable one other than Him is sometimes able and other times unable
المصدر : غرر الحكم ودرر الكلم
لَوْ كَانَ لِرَبِّكَ شَرِيكٌ لَأَتَتْكَ رُسُلُهُ
If your Lord had a partner, then his prophets would [also] have come to you