Praise be to Allah.
Isbaal means making the clothes so long that they come beneath the ankle. The prohibition on isbaal is mentioned in the hadeeth of the Prophet (peace and blessings of Allaah be upon him): “Whatever part of the lower garment comes beneath the ankles is in the Fire.” Narrated by al-Bukhaari, 5787. This warning does not apply to something that is makrooh or permissible, rather the warning of Hellfire usually comes to the one who does a haraam action.
If a man says, “I am not doing it to show off,” he is praising himself and that is not acceptable. The hadeeth is general in meaning and includes everyone who lets his garment hang down, whether that is out of pride or otherwise.
With regard to the one who lets his garment hang down out of pride, his punishment will be more severe. The Prophet (peace and blessings of Allaah be upon him) said: “Isbaal may apply to the izaar (lower garment), shirt and turban. Whoever lets any of them hang down out of pride, Allaah will not look at him on the Day of Resurrection.” Narrated by Abu Dawood, 4085; al-Nasaa’i, 5334; with a saheeh isnaad.
With regard to wearing see-through clothing that shows the ‘awrah, this is haraam and is not permissible, because the one who does that is not considered to be covering his ‘awrah.
The same applies to tight clothes which show the size and shape of the ‘awrah and are a cause of fitnah (temptation). We are living in an age where desires are easily provoked and there is a great deal of fitnah, so how can it be appropriate for the Muslim youth to make matters worse and expose themselves to the wrath of the Lord?