Since the chanting of Devi Mahatmya leads to all the luck and good things in the world and at the end salvation, Lord Prameshwara decided to impose certain conditions to get that full benefit. This is the nail (keelakam) that he has put.

Rishir Uvacha:-

1.Vishudha gnana dehaya trivedi divya chakshushe,
Sreya prapthi nimithaya nama somardha dharine.

The sage told:-

My salutations to that Parameshwara(The greatest lord) who is in the form of doing extreme penance, who has three holy eyes , who is the prime cause leading to salvation and who wears the crescent.

2.Sarvamethad vijaniyath manthranam abhi keelakam,
Sopi kshemavapnodhi sathatham japa thathpara.

3.Sidhyunthyuchadanadheeni vasthuni sakalanyapi,
Ethena sthuvadham devi sthothramathrena sidhyathi.

For getting victory in reading the Devi Mahatmyam, reading this would remove all the spokes in the way of getting result. He who reads this also gets good times and gets all those which are not attainable. Even to one who praises Goddess with only Devi Mahatmya, she becomes pleased.

4.Na manthroushadham thathra na kinchid api vidhyathe,
Vina japyena sidhyatha sarvamuchadanadhikam.

5.Samagranyapi sidhyathi, loka sanka mimam hara,
Kruthwa nimanthrayamasa sarvamedhamidham shubham.

That man needs no other chant (than Devi Mahatmya) or medicine. Without any other he would realise all his needs. He realizes fully all his wishes, for the great god (Shiva), taking in to account the normal doubts among people, after composing this Keelaka also made it not necessary for him to read others.

6.Sthothram vai Chandikayasthu thacha guhyam chakara sa,
Samapthirna cha punyasya tham yadavaniyanthranam.

The Lord Parameshwara made the “Devi Mahatmya” as secret and since there is no end to the blessings that can be received by it, made the method of reading it very secret.

7.Sopi kshemamapnothi sarvameva na samsaya,
Krushnayam vaa chaturdasyam ashtamyam va samahitha,

8.Dadthi prathi gruhnathi nanyaidaisha praseedathi.
Itham ropena keelena Mahadevena keelitham,

9.Yo nishkeelam vidayainam nithyam japathi samsphutam,
Sa sidha sagana sopi gandharvo jayathe avana.

There is no doubt that he gets all comforts. He has to observe with complete concentration all the necessary charities and rules laid down for the chanting on the fourth or fourteenth day after the NEW moon.Unless he does that the goddess will not be pleased with him.. This has been fixed like a driving nail by Lord Parameshwara. He who reads it without this would become one of the assistants of the Goddess.

(Because God thought just by chanting this every body would become equal to gods, whether they are good or bad, he has put this condition.(nail). He has told that this japa has to be done on Krishna ashtami or Krishna Chathurdasi. Before the Japa he should give away all his wealth to the goddess and receive back from her as prasada that which is just sufficient for him. He should then do the chanting with full concentration and according to the method prescribed. If he does like that, then only he will get the full effect of chanting the manthra.)

10.Na chaivapyata thasthasya bhayam kwapeeha jayathe,
na apamruthyu vasam yathi mrutho mokshamapnuyath.

He will have no fear any where in the world, he will never be subject to untimely death and after death he will attain salvation.

11.Jnathwa prabhya kurveetha hyakurvano vinasyathi,
Thatho jnathtwaiva sambannamidham prabhyadhe budha.

This method should be understood well and then only the chanting should be started. If it is not done this way it will not be effective. So learned people do this way.

12.Soubhagyadhi cha yath kinchid drusyathe lalanajane,
That sarvam that prasadena thena japyamidham shubham.

Even ladies who do not know the method by chanting it will get some small benefits like beauty.So this has necessarily be chanted.

13.Sanaisthu japyamane asmin sthothre samathi ruchagai,
Bhavathyeva samagrapi thatha prabhyameva thath.

If this is chanted without sound you will get riches and if chanted loudly complete wealth could be got and so this should be chanted loudly.

14.Iswaryam yath prasadena soubhagya maraogya sampada,
Sathruhani paro moksha sthuyathe saa na kim janai.

How is it that with this knowledge that this chanting would lead to wealth, luck, heath and destruction of ones enemies, some people are still not chanting it?

Devi Keelakam Samaptham
The nail of the Goddess ends