Who break the covenant of Allāh after contracting it and sever that which Allāh has ordered to be joined and cause corruption on earth. It is those who are the losers.
In his Tafsir, As-Suddi reported that Ibn `Abbas, Ibn Mas`ud, and some Companions said; "When Allah gave these two examples of the hypocrites" meaning Allah's statements,
مَثَلُهُمْ كَمَثَلِ الَّذِى اسْتَوْقَدَ نَاراً
(Their likeness is as the likeness of one who kindled a fire), and,
أَوْ كَصَيِّبٍ مِّنَ السَّمَآءِ
(Or like a rainstorm from the sky), "The hypocrites said, `Allah's far more exalted than for Him to make such examples.' So Allah revealed these Ayat (2:26-27) up to:
هُمُ الْخَـسِرُونَ
(Who are the losers)". Sa`id said that Qatadah said, "Allah does not shy away from the truth when He mentions a matter as a parable, whether this matter is significant or not. When Allah mentioned the flies and the spider in His Book, the people of misguidance said, `Why did Allah mention these things.' So Allah revealed;
The cutting asunder of what Allah has commanded should be joined includes all kinds of relationships -- the one between Allah and His servant, the one between a man and his parents and relatives, between him and his neighbours and friends, between one Muslim and another, between one man and another. Actually, Islam means fulfilling one's obligations with regard to all these relationships,. And this is also the way to follow the Shari'ah. Deficiency in fulfilling these obligations produces all kinds of disorder among men, and thus the transgressors end up by being destructive for others and for themselves. It is these, the Holy Qur'an says, who are the losers -- in this world as in the other.
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 25–27
The call of truth is indisputably marked with a divine radiance. Its inimitable style and its irrefutable reasoning go to show that it is a message from God. Those who deny it, irrespective of this, shall find no refuge in God’s universe. Those who find God in the word of God are already given a glimpse of the next world. They are the ones who shall be admitted into the gardens of Paradise.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.