It is not mandatory to be taahir...
It is not mandatory to be taahir, like after going to the toilet, when declaring ihraam. Thus one who is in the state of Janaabah, or a Ha’edh [a woman who is experiencing the haydh – the monthly menses], or one who does not have wudhu may declare and assume ihraam. However, if one wanted to perform the ihraam prayers, the prayers would not be valid unless [being taahir and] with wudhu.
If due to oversight or ignorance of the ruling, one wore the ihraam garments without removing his normal clothing, then whenever he remembered or realised the ruling of the case, must remove his normal clothing, and his ihraam is valid. The same is also applicable if an individual, after declaring and assuming ihraam, wears his normal clothing, either having forgotten or due to ignorance of the case.
There is no objection to wearing more than the normal set of ihraam garment, whether at the time of declaring ihraam or afterwards, to protect oneself against the weather. 2. Niyyah Declaration of niyyah or intention is mandatory for ihraam. It is the resolution of performing ihraam, seeking nearness to Allah Almighty. The meaning of ihraam is to abstain from and relinquish a number of things, details of which will be given later.
In an exception to other acts of worship, it is recommended that the niyyah is verbally uttered in this case. After removing all sewn clothing, and wearing the two ihraam garments, one should say, “I declare and assume the ihraam for the Umrah of TAMATTU' for Hajjat-al-Islam seeking nearness to Allah Almighty”. 3.
Talbiyah Without talbiyah, ihraam would not be established, (although) in the case of Qiraan Hajj, the ihraam is established with talbiyah, or marking the animal with a sign or a collar. The obligatory talbiyah18 takes the following form of reciting [the four phrases]: 18 Talbiyah literally means compliance, fulfilment, or carrying out the orders of Allah Almighty. Labbayk Allahumma Labbayk. I heed to your call O Lord, I heed. Labbayka Laa Shareeka Laka Labbayk.
I heed that (O You) You have no partner, I heed. In Nal-Hamda, Wan Ne‘mata, Laka Wal Mulk. Truly, All the Praise, and the Bliss, are Yours and the Sovereignty is too. Laa Shareeka Laka Labbayk. The last word may be added as a recommended precaution. There is no partner of Yours, I heed. It is obligatory that the talbiyah is recited at least once, and with it the ihraam is established.