Let's all start our I'tikaaf! The above niyyat is for men, because if you understand Arabic, "Ma Dumtu Fil Masjid" means " sepanjang aku berada di Masjid" where we women don't go to. Therefore it's sufficient for us to say "Nawaitul I'tikaafa lillahi Azza Wajalla" which means " Sahaja aku beri'tikaaf / menunaikan I'tikaaf kerana Allah Azza Wajalla"...
Why Do / Should We Perform I'tikaaf?
1) To concentrate on our Ibadah and to get closer to Allah Ta'ala.
Ibn Abbas R.A. relates that Rasulullah S.W. said, “The person performing I’itikaaf remains free from sins, and he is indeed given the same reward as those who do righteous deeds (in spite of not having done those deeds as a result of having been secluded in the masjid)”.
Reported in Mishkaat from Ibn Majah
3) To search for Laylatul Qadar (while remaining in the state of performing Ibadah)
Another amazing point is that a person performing I'tikaf is granted the reward of waiting for Solah. And the reward of waiting for Solah is that the person is granted the rewards of being in Salaah. Therefore, it is as if the person forming the intention for I’tikaaf has begun Salaah on the eve of the twentieth of Ramadaan and remains engaged in this Salaah for a full ten days and nights, till the sighting of the crescent for Eid after which he turns for Salaam and completes his Salaah. While fast asleep, he is in Salaah! While wide a wake, he is in Salaah! While eating, he is in Salaah! While drinking, he is in Salaah!
Let's start now, there's still time. It's better late than never! May Allah give us Taufeeq (ability) to make a'mal.