I will list the supportive evidence of my views that Niqab is not Wajib. Others in favor of Niqab being Wajib can post their supportive evidence. Personally, it is up to the ladies to wear Niqab or Not to wear Niqab.
The following is the supportive evidence from Islam that Scholars who say Niqab is not Wajib used.
"Permanent
Niqab or face veil is not an Islamic requirement; it is a personal choice since
Niqab is forbidden during
Ihram according to most contemporary scholars based on the following
fatwa:
The Prophet (peace be upon him) said:
“A woman who is in the state of Ihram (during Hajj or Umra) may not wear a niqab or gloves.” (Al-Bukhari)
However, she is allowed to temporary cover her face whenever non-
Mahram men pass by her according to Aisha’s narration:
“Whenever rides pass by us while in Ihram with the Prophet (peace be upon him), as they get closer we covered our faces and when they pass us we removed it” (Abu Dawud)
If a woman covers her face with a
burqu (mask) or
niqab, permanent face cover, she has broken one of the rules of
Ihram and must pay a
fidyah (redemption) according to the following verse in the Quran which is translated as:
{…then you should make redemption by fasting, or alms-giving, or ritual sacrifice…} (Al-Baqara, 2:196)
She will not collect any sin if she makes redemption. However, many scholars are of the opinion that a
fidyah is not required.
Most contemporary scholars view that
hijab fulfills the requirements for Muslim woman’s dress when in public and
niqab is a step beyond that. The following paragraphs explain this view.
The permissibility of exposing the face and hands is based on the Quranic verse:
{And say to the believing women that they cast down their looks and guard their private parts and do not display their ornaments except what appears thereof} (An-Nur 24: 31)
“
Except what appears thereof” means the face and the hands as confirmed by the Prophet’s
hadith (peace be upon him); he (peace and blessings be upon him) said to Asma’, daughter of Abu Bakr (may Allah be pleased with them):
“O Asma’! Once a girl reaches puberty, nothing of her body may be seen (by non-mahrams) except this and these, (he pointed to his face and hands while saying so).” (Abu Dawud, Al-Albani Classified it as Hasan)
"