The Truthful among the Israelites
The verse 159 said: وَمِن قَوْمِ مُوسَىٰ أُمَّةٌ يَهْدُونَ بِالْحَقِّ وَبِهِ يَعْدِلُونَ ﴿159﴾ '"Among the community of Musa there are people who guide to the truth, and do justice thereby." That is, there is a group among the Israelites who follows the truth and decides their controversies according to the dictates of the Truth - Islam. Which are the people referred to in this verse as following the truth among the Israelites? This refers to the people who faithfully followed the commandments of the Torah and the Injil at the time they were revealed, and those who readily accepted the faith of Islam after the appearance of the Holy Prophet ﷺ according to the predictions contained in the Torah and the Injil. The Holy Qur'an has referred to this group in a number of verses in commendable terms. There is a verse which said: مِّنْ أَهْلِ الْكِتَابِ أُمَّةٌ قَائِمَةٌ يَتْلُونَ آيَاتِ اللَّـهِ آنَاءَ اللَّيْلِ وَهُمْ يَسْجُدُونَ "Among the people of the Book there are those who are steadfast, they recite the verses of Allah in the night hours, and they prostrate." (3:113)
الَّذِينَ آتَيْنَاهُمُ الْكِتَابَ مِن قَبْلِهِ هُم بِهِ يُؤْمِنُونَ ﴿52﴾
"Those to whom We gave the book before this, they do believe in this (Qura'n) ". (28:52)
Under the comments on this verse we find a narrative in the commentaries of Ibn Jarir and Ibn Kathir رحمۃ اللہ علیہما . A group of Israelites who greatly despised the corrupt practices of the Israelites had prayed Allah for having a separate land away from the other tribes so that they might practice according to the original faith preached by the Prophet Musa (علیہ السلام) ، Allah carried them to a land somewhere in the Far East where they faithfully practiced their faith.
Another favour of Allah bestowed upon them was that in the time of the Holy Prophet ﷺ they were granted an opportunity to embrace Islam directly on the hands of the Holy Prophet. In the night of Ascension (شَبِ مِعرَاج ) the Archangel Jibra'il (علیہ السلام) (Gabriel) took the Holy Prophet ﷺ to these people on the way to heavens. They accepted the faith and the Holy Prophet ﷺ taught them some Surahs (chapters) of the Holy Qur'an.
The Prophet of Allah asked them if they had some means of weighing and measuring and what other means of subsistence did they have? They answered that their usual practice was that they cultivated the land and collected the whole produce together in a heap. The people came and took from it according to their need. They said, "We do not, therefore, need any weights and measures." The Holy Prophet ﷺ asked them if any one of them ever told lies. They said that no one among them ever told lies because it was a usual practice that any person speaking a lie was burnt up by a heavenly fire. He asked them as to why all their houses were of the same type? They answered, that it was to avoid the possibility of showing off one's affluence as compared to others. He asked them why they had built up their graves in front of their houses? They said that this made them remember their death all the times. After the Holy Prophet returned from heavens to Makkah, this verse was revealed to him. Al-Qurtubi, under the comments of this verse has narrated this event along with other suggestions and has remarked that this narrative was not authentic. Ibn Kathir, however, has termed it as an unusual event but did not reject it.
In short, this verse makes us understand that there has always been a group among the Israelites who followed the Truth. Be they the people described above or the ones who embraced Islam after the appearance of the Holy Prophet ﷺ .