Page 009 | سورة البقرة من الاية 58 الى 61
When there are 2 similar letters next to each other and the first is saakinah then you do idghaam. We see it on this page, adhrib-bi asaak. So the first word idhrib ends with a ba saakinah and the second ba has a harakah. So we pronounce it as one baa mushadadah...pressing the lips on the first baa and opening them on the second baa.
Later on the page we see qeela lahum. They are 2 similar letters but both have harakaat so we don’t do idghaam because in this qiraah, the first one should be saakinah to do idghaam.
Later in the page we see asaw-wa. The first one ends with a waw saakinah and the second begins with a waw mutaharrik.
We said before that when the first letter is sakin and the second is mutaharik we do idgham, except if the first letter is a madd letter, but here the waw is sakinah and the letter before it has fatha so it is not a madd letter...so it is sakinah and the condition for idgham applies. We do idghaam. So we merge and put a shaddah. Asawwa.