It is permissible to take for a Miswak all kinds of tree twigs provided these aren't hazardous or poisonous. It is prohibited to utilize a Miswak from a poisonous tree. Miswaks from the following trees aren't permissible:
Our Holy Prophet (Peace Be upon Him) Forbade the Usage of Raihaan as Miswak as it leads to the disease, Juz-zaam
Listed below are the kinds of Miswak recommended:
"And, the finest of Miswaks is the Peelo, then the Olive."
The ideal kind of Miswak is that which is obtained from the Peelo tree. The miswak of the Peelo tree is incredible for getting the sparkle or glitters of the teeth. Our Holy Prophet (Peace Be upon Him) likewise lauded and endorsed the Peelo tree for Miswak usage. Apart from recommending the Peelo tree, Holy Prophet (Peace Be upon Him) together with the Companion (May Allah be Pleased with them) utilized Miswaks of this tree. Companions of Imam Shafi (R) have shown Agreement of Opinion among them on the point that the usage of the Peelo Miswak is Mustahab.
Our Holy Prophet (Peace Be upon Him) has voiced highly of the Miswak of this tree as well. The following Hadith reveals the importance of the Olive tree Miswak:
"Use the Miswak of the Olive tree. It's the Miswak of an auspicious tree. It cleans and makes wholesome the mouth. It erases the yellowishness of the teeth. It is my (i.e. Rasulullah's) Miswak and the Miswak of the Prophets who arrived before me."
In another Hadith it's stated that in the absence of the Peelo tree the Olive tree could be utilized, and in the absence of the Olive Miswak, the Bitam tree Miswak could be utilized.
If none of the three aforementioned kinds of Miswak is obtainable, a Miswak of any bitter tree can be taken.
" . . Afterwards it is recommended to utilize a Miswak of a sour tree since the Miswak of a sour tree takes off odor of the mouth to a greater extent."