What is the ruling on muslims hugging the person who told shahādah (testimony of faith) right after that. Is there is any dalīl for doing it? What is the Sunnah way to embrace the new muslim after taking shahādah?
Shaykh Abū Bilāl answered saying:
There is no problem in wishing the person by hugging him. Shaykh mentioned the story of Kʿab bin Mālik as proof for this, that he hugged the person who gave him the good news of acceptance of his repentance . The scholars use this as proof for permissibility of hugging a person who was not a traveler. Hugging is well known for a person who has returned from journey.
The proof for hugging for a person who has returned from a journey was cited in an answer by The Permanent Committee for Scholarly Research and Ifta’:
The sixth question of Fatwa no. 12228
Q6: What is the ruling on Muslims kissing each other’s faces? Are there narrations from the Ṣaḥābah (Companions of the Prophet) in this regard?
A: It is preferable to shake hands in the regular manner unless a person has just come from travel, then embracing is permissible. Anas (may Allah be pleased with him) narrated: “When the Ṣaḥābah of the Prophet (peace be upon him) met each other, they used to shake hands; and when they came from travel, they would embrace each other.” (Related by aṭ-Ṭabarānī with a good Sanad (chain of narrators). May Allah grant us success. May peace and blessings be upon our Prophet Muḥammad, his family, and Companions. Source: alifta.net
Shaykh Al-ʿUthaymīn has told about the permissibility of hugging after ʿĪd prayer as following:
“These things (hugging, shaking hands, wishing each other) does not have any problem, as the people do not do these as an act of worship to get near to Allāh and they do this as habitual practice and as honoring each other”. Majmūʿ Fatāwa wa Rasāʾil ibn Al-ʿUthaymīn – 16/128
So there is no problem in hugging the person who pronounced the Shahādah as a wishing.
Allāh knows best.
Compiled by: ʿAbdun-Nūr al-Hindī
 I could not find reference to this narration. And the Shaykh said that he remembers reading it but he did not remember the reference.