The difference between their saying “a saheeh hadeeth” and their saying “its isnaad is saheeh”

Question

Praise be to Allah.

Firstly:

The muhaddithoon state that the saheeh hadeeth which is most
likely attributable to the Prophet (peace and blessings of Allaah be
upon him) is the hadeeth which fulfils all of the five following
conditions:

1.Each of its narrators is of
good character

2.Each of its narrators has a
precise memory

3.The isnaad is uninterrupted
from beginning to end

4.The hadeeth is sound and free
of any shudhoodh (irregularity) in its isnaad or matn (text)

5.The hadeeth is sound and free
of any ‘illah (fault) in its isnaad or text.

This has been discussed in the answer to question no.
79163.

Secondly:

The fourth and fifth conditions are among the most precise of
conditions and the most difficult for the critic, because proving them
required intense research and precision, bringing together all the isnaads
and narrations of the hadeeth, as well as extensive experience in the
sciences of hadeeth and specialization in criticism. Hence many of the later
muhadditheen chose to err on the side of caution in their verdicts, and they
limited their studies to checking the outward appearance of the isnaad to
check whether it met the first three conditions, so if a specific isnaad met
these three conditions they would say “a saheeh isnaad”, so as to alert the
reader to the fact that they were only verifying that it met the first three
conditions, and not the fourth and fifth, so that the reader would be aware
of what this muhaddith meant.

Al-Haafiz ibn al-Salaah (may Allaah have mercy on him) said:

When they say “This hadeeth has a saheeh isnaad or a hasan
isnaad” instead of “this is a saheeh hadeeth or a hasan hadeeth”, that is
because it may be said that this hadeeth has a saheeh isnaad but it is not
saheeh per se because it is shaadhdh (odd) or mu’allal (faulty). End quote.

Muqaddimah fi ‘Uloom al-Hadeeth
(p. 23)

Ibn Katheer says:

The fact that the isnaad is deemed to be saheeh or hasan does
not necessarily mean that the same applies to the text, because it may be
shaadhdh (odd) or mu’allal (faulty). end quote.

Ikhtisaar ‘Uloom al-Hadeeth (p.
43).

Al-‘Iraaqi said in his Alfiyyah:

The ruling that the isnaad is saheeh or hasan does not
necessarily apply to the text. End quote.

Al-Tabsirah wa’l-Tadhkirah
(1/107).

Thirdly:

Nevertheless, there may be an exception to this
differentiation if it is known that a particular imam does not make this
distinction between the two terms “a saheeh isnaad” and “a saheeh hadeeth”
in his terminology. An imam – especially if he is one of the earlier
scholars – may say “a saheeh isnaad” when he means that the hadeeth itself
is saheeh, and that it meets all five conditions.

Al-Haafiz Ibn al-Salaah (may Allaah have mercy on him) said:

But a reliable scholar may say in his book “it has a saheeh
isnaad” and not mention any ‘illah (fault), or criticize it, so it may be
understood that he deems it to be saheeh in and of itself, because the
absence of any ‘illah (fault) or qaadih (flaw) is the basic principle. And
Allaah knows best. End quote.

Muqaddimah fi ‘Uloom al-Hadeeth
(p. 23).

Al-Haafiz Ibn Hajar (may Allaah have mercy on him) said:

It seems to me that the correct view is that a distinction
should be made between the one who differentiates when describing hadeeth as
saheeh, stating it in either specific or general terms, and the one who does
not do so.

The one who is known from studying his books to make this
distinction should be viewed accordingly, so when he speaks in general terms
it should be understood as referring to both the isnaad and the matn, and
when he speaks in specific terms it should be understood as referring to the
isnaad only.

And it maybe said concerning the one who is known to describe
hadeeth only in specific terms all the time what we quoted above. End quote.

Al-Nukat ‘ala Ibn al-Salaah
(1/474).

And Allaah knows best.